As a condensed water treatment device for an internal combustion engine, known is the one which stores, in a condensed water tank, condensed water generated in an EGR cooler included in an exhaust system, and injects the condensed water to an intake passage when the storage water quantity of the condensed water tank reaches a predetermined quantity (Patent Literature 1). The condensed water supplied to the intake passage is led into a cylinder with intake gas to vaporize. Thereby, the combustion temperature is suppressed. As a result of that, the generation quantity of NOx because of combustion is suppressed. In addition, as literatures of prior art relating to the present invention, there are Patent Documents 2 and 3.